Metallic tube connections for fluid power and general use —

(1)

Metallic tube connections for fluid power and general use —

Part 1:

24° cone connectors

Raccordements de tubes métalliques pour transmissions hydrauliques et pneumatiques et applications générales —

Partie 1: Raccords coniques à 24°

INTERNATIONAL

STANDARD ISO

8434-1

Third edition 2018-07

Reference number ISO 8434-1:2018(E) Corrected version 2018-10

(2)

COPYRIGHT PROTECTED DOCUMENT

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester.

ISO copyright office

CP 401 • Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Fax: +41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland

(3)

ISO 8434-1:2018(E)

Foreword ...v

Introduction ...vi

1 Scope ...1

2 Normative references ...1

3 Terms and definitions ...2

4 Materials ...3

4.1 General ...3

4.2 Connector bodies ...4

4.3 Nuts ...4

4.4 Cutting rings ...5

4.5 O-rings ...5

5 Pressure/temperature requirements ...5

6 Designation of connectors ...9

7 Requirements for tubes ...12

8 Across‑flats dimensions and tolerances ...12

9 Design ...12

9.1 Connectors ...12

9.2 Dimensions ...12

9.3 Passage tolerances ...13

9.4 Angular tolerances ...13

9.5 Contour details ...13

9.6 Ports and stud ends ...13

9.7 Stud end sealing ...13

10 Screw threads ...13

10.1 Cone ends and nuts ...13

10.2 Stud ends (connection ends) ...13

11 Manufacture ...13

11.1 Construction ...13

11.2 Workmanship ...14

11.3 Finish ...14

11.4 Corners ...14

12 Assembly instruction ...14

13 Procurement information ...15

14 Marking of components ...15

15 Performance and qualification test ...15

15.1 General ...15

15.2 Repeated assembly test ...15

15.3 Proof test ...15

15.4 Burst pressure test ...15

15.5 Cyclic endurance (impulse) test ...15

15.6 Vibration test ...15

15.7 Leakage (gas) test ...16

15.8 Overtightening test ...16

15.8.1 Connectors with cutting rings ...16

15.8.2 Connectors with O-ring seal cone (DKO) ...16

15.9 Vacuum test ...16

16 Identification statement (reference to this document) ...16

ISO 8434-1:2018(E)

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www .iso .org/patents).

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www .iso .org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 4, Connectors and similar products and components.

This third edition cancels and replaces the second edition (ISO 8434-1:2007), which has been technically revised.

A list of all the parts in the ISO 8434 series, can be found on the ISO website.

This corrected version of ISO 8434-1:2018 incorporates the following corrections:

— Table 4: missing data in the Thread column of Series L and S has been inserted.

— Table 21: missing data in the s1 column of Series L and S has been inserted.

(6)

Introduction

In fluid power systems, power is transmitted and controlled through a fluid (liquid or gas) under pressure within an enclosed circuit. In general applications, a fluid may be conveyed under pressure.

Components may be connected through their ports by connections (connectors) and conductors (tubes and hoses). Tubes are rigid conductors; hoses are flexible conductors.

(7)

Metallic tube connections for fluid power and general use — Part 1:

24° cone connectors

1 Scope

This document specifies the general and dimensional requirements for 24° cone connectors using cutting ring and O-ring seal cone (referred to as DKO) suitable for use with ferrous and non-ferrous tubes with outside diameters from 4 mm to 42 mm inclusive. These connectors are for use in fluid power and general applications within the limits of pressure and temperature specified in this document.

They are intended for the connection of plain end tubes and hose fittings to ports in accordance with ISO 6149-1, ISO 1179-1 and ISO 9974-1. (See ISO 12151-2 for a related hose fitting specification.)

These connectors provide full-flow connections in hydraulic systems operating to the working pressures shown in Table 1. Because many factors influence the pressure at which a system performs satisfactorily, these values are not intended to be understood as guaranteed minimums. For every application, sufficient testing is meant to be conducted and reviewed by both the user and manufacturer to ensure that required performance levels are met.

NOTE 1 For new designs in hydraulic fluid power applications, see the requirements given in 9.6. Where the requirements of the application allow for the use of elastomeric seals, connector designs that conform to International Standards and incorporate elastomeric sealing are preferred.

NOTE 2 For use under conditions outside the pressure and/or temperature limits specified, see 5.4.

This document also specifies a performance and qualification test for these connectors.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD and 100 IRHD)

ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions, tolerances and designation

ISO 724, ISO general-purpose metric screw threads — Basic dimensions

ISO 965-1, ISO general purpose metric screw threads — Tolerances — Part 1: Principles and basic data ISO 1127, Stainless steel tubes — Dimensions, tolerances and conventional masses per unit length

ISO 1179-1, Connections for general use and fluid power — Ports and stud ends with ISO 228-1 threads with elastomeric or metal-to-metal sealing — Part 1: Threaded ports

ISO 1179-2, Connections for general use and fluid power — Ports and stud ends with ISO 228-1 threads with elastomeric or metal-to-metal sealing — Part 2: Heavy-duty (S series) and light-duty (L series) stud ends with elastomeric sealing (type E)

INTERNATIONAL STANDARD ISO 8434-1:2018(E)

(8)

ISO 1179-4, Connections for general use and fluid power — Ports and stud ends with ISO 228-1 threads with elastomeric or metal-to-metal sealing — Part 4: Stud ends for general use only with metal-to-metal sealing (type B)

ISO 3304, Plain end seamless precision steel tubes — Technical conditions for delivery ISO 3305, Plain end welded precision steel tubes — Technical conditions for delivery ISO 3601-3, Fluid power systems — O-rings — Part 3: Quality acceptance criteria

ISO 4759-1:2000, Tolerances for fasteners — Part 1: Bolts, screws, studs and nuts — Product grades A, B and C ISO 5598:2008, Fluid power systems and components — Vocabulary

ISO 6149-1, Connections for hydraulic fluid power and general use — Ports and stud ends with ISO 261 metric threads and O-ring sealing — Part 1: Ports with truncated housing for O-ring seal

ISO 6149-2, Connections for hydraulic fluid power and general use — Ports and stud ends with ISO 261 metric threads and O-ring sealing — Part 2: Dimensions, design, test methods and requirements for heavy- duty (S series) stud ends

ISO 6149-3, Connections for hydraulic fluid power and general use — Ports and stud ends with ISO 261 metric threads and O-ring sealing — Part 3: Dimensions, design, test methods and requirements for light- duty (L series) stud ends

ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests

ISO 9974-1, Connections for general use and fluid power — Ports and stud ends with ISO 261 threads with elastomeric or metal-to-metal sealing — Part 1: Threaded ports

ISO 9974-2, Connections for general use and fluid power — Ports and stud ends with ISO 261 threads with elastomeric or metal-to-metal sealing — Part 2: Stud ends with elastomeric sealing (type E)

ISO 9974-3, Connections for general use and fluid power — Ports and stud ends with ISO 261 threads with elastomeric or metal-to-metal sealing — Part 3: Stud ends with metal-to-metal sealing (type B)

ISO 19879, Metallic tube connections for fluid power and general use — Test methods for hydraulic fluid power connections

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http: //www .electropedia .org/

— ISO Online browsing platform: available at http: //www .iso .org/obp 3.1connector

device that connects tubes, hoses or pipes to each other or to components [SOURCE: ISO 5598:2008, 3.2.122]

3.2connection

assembly of parts belonging to piping 3.3fastening thread

terminal thread of a complete connector

(9)

ISO 8434-1:2018(E)

3.4run

two principal, axially aligned outlets of a tee connector or cross connector [SOURCE: ISO 5598:2008, 3.2.632]

3.5branch

side outlet(s) of a tee connector or cross connector [SOURCE: ISO 5598:2008, 3.2.81]

3.6chamfer

removal of a conical portion at the entrance of a thread, used to assist assembly and prevent damage to the start of the thread

3.7face‑to‑face dimension

distance between the two parallel faces of axially aligned outlets of a connector 3.8face‑to‑centre dimension

distance from the face of an outlet to the central axis of an angularly disposed outlet 3.9assembly torque

torque required to achieve a satisfactory final connection [SOURCE: ISO 5598:2008, 3.2.46]

3.10maximum working pressure

highest pressure at which a system or sub-system is intended to operate in steady-state operating conditions

Note 1 to entry: For components and piping see also related term “rated pressure”.

[SOURCE: ISO 5598:2008, 3.2.429, modified — NOTE 2 deleted.]

4 Materials 4.1 General

Figures 1 and 2 show the cross-sections and component parts of typical 24° cone connectors.

(10)

Key 1 body 2 nut

3 cutting ring

Figure 1 — Cross‑section of typical 24° cone connector with cutting ring

Key 1 body 2 nut

3 DKO-end (including O-ring)

Figure 2 — Cross‑section of typical 24° cone connector with O‑ring seal cone (DKO) end

4.2 Connector bodies

Bodies shall be manufactured from carbon steel that will provide the minimum pressure/temperature requirements specified in Clause 5. They shall have characteristics that make them suitable for use with the fluid to be conveyed and that will provide an effective joint. Weld connector types and weld-on nipples shall be made of materials classified as suitable for welding.

For bodies manufactured from stainless steel and copper alloys, the pressure/temperature ratings need to be defined by the manufacturer.

4.3 Nuts

Nuts to be used with carbon steel bodies shall be made of carbon steel, and those for use with stainless steel bodies shall be made of stainless steel, unless otherwise specified. Nuts to be used with copper alloy bodies shall be made of a material similar to the bodies.

(11)

ISO 8434-1:2018(E)

4.4 Cutting rings

4.4.1 The ring material shall be compatible with the fluid to be conveyed and provide an effective joint.

4.4.2 Steel cutting rings are to be used in combination with other steel connector components and steel tubes.

4.4.3 Stainless steel cutting rings are to be used in combination with other stainless steel connector components and stainless steel tubes.

4.4.4 Brass cutting rings are to be used in combination with other brass connector components and copper tubes.

4.4.5 Other combinations of materials shall be agreed upon between the purchaser and supplier.

4.5 O‑rings

Unless otherwise specified, for use with petroleum-based hydraulic fluids at the pressure and temperature requirements given in Clause 5 and Table 1, O-rings for use with connectors in accordance with this document shall be made of acrylonitrile-butadiene rubber (NBR) with a hardness of (90 ± 5) IRHD, measured in accordance with ISO 48, and shall conform to the dimensions given in Table 7 and shall meet or exceed the O-ring quality acceptance criteria of ISO 3601-3, grade N. In those cases where the pressure and temperature requirements of this document and/or the hydraulic fluid used in the system differ from those specified in Clause 5 and Table 1, the connector manufacturer shall be consulted to ensure that an appropriate O-ring material is selected.

5 Pressure/temperature requirements

5.1 Connectors in conformance with this document made of carbon steel shall meet or exceed without leakage the requirements from a vacuum of 6,5 kPa (0,065 bar) absolute pressure to the working pressures given in Tables 1 to 3 when used at temperatures between −40 °C and +120 °C with petroleum-base hydraulic fluids.

5.2 Connectors conforming to this document can contain elastomeric seals. Unless otherwise specified, connectors are made and delivered with elastomeric seals for use within the specified working temperature range with petroleum-base hydraulic fluids. The use of these connectors and elastomeric seals with other hydraulic fluids may result in a reduced working temperature range or may render the connectors unsuitable for the application. Manufacturers may supply, upon request, connectors with elastomeric seals for use with hydraulic fluids other than petroleum-base hydraulic fluids which will meet the specified working temperature range of the connectors.

5.3 The connector assembly shall meet or exceed all applicable performance requirements given in Clause 15. Testing shall be conducted at room temperature.

5.4 For applications under conditions other than the pressure and/or temperature limits given in Tables 1 to 3 and in 5.1 and 5.3, the manufacturer shall be consulted.

5.5 According to different applications and different pressure ratings, there are three series of connector, designated by

— LL, for extra light-duty,

— L, for light-duty, and

— S, for heavy-duty.

Metallic tube connections for fluid power and general use —

Metallic tube connections for fluid power and general use —

Part 1:

24° cone connectors

INTERNATIONAL

STANDARD ISO

8434-1

COPYRIGHT PROTECTED DOCUMENT

ISO 8434-1:2018(E)

Contents

ISO 8434-1:2018(E)

Foreword

Introduction

Metallic tube connections for fluid power and general use — Part 1:

24° cone connectors

1 Scope

2 Normative references

INTERNATIONAL STANDARD ISO 8434-1:2018(E)

3 Terms and definitions

ISO 8434-1:2018(E)

4 Materials 4.1 General

4.2 Connector bodies

4.3 Nuts

ISO 8434-1:2018(E)

4.4 Cutting rings

4.5 O‑rings

5 Pressure/temperature requirements